THUBTEN Jigme Norbu, who has died aged 86, was the eldest brother of the Dalai Lama and a tenacious symbol of the Tibetan struggle for independence. He was aged 87 according to Tibetan tradition which considers a person to be one year old at the moment of their birth.

A major Buddhist figure in his own right - he was believed to be the 23rd reincarnation of a famous high lama - Norbu had been in declining health after a series of strokes. He died of natural causes in Indiana, his home for four decades of exile.

Norbu taught Tibetan studies for more than 20 years at Indiana University, Bloomington. Amid cornfields on the outskirts of town he created a Tibetan cultural centre that has drawn thousands of visitors, including the Dalai Lama.

The two brothers disagreed on the status of Tibet. The Dalai Lama favours making it an autonomous state, similar to Hong Kong, while Norbu insisted on independence. He was a co-founder of the International Tibet Independence Movement, which has sponsored more than a dozen walks across the United States and abroad to draw attention to Tibet's suffering under Chinese rule.

The oldest son in a farming family of six children, Norbu was born in northeast Tibet on August 16th, 1922. At four he was identified as the reincarnate of a revered monk, Tagtser. At eight he left home to enter the Kumbum Monastery near the Chinese border, where he rose at 4am every day to memorise 2,000 pages of Buddhist scripture.

He was 15 when high lamas declared that his then 2-year-old brother was the 14th Dalai Lama, the spiritual and political leader of Tibet.After his brother's elevation, he moved from Kumbum to Lhasa, the Tibetan capital, to join his family.At 27, he returned to Kumbum as abbot of the monastery, which was one of Tibet's largest, with more than 4,000 monks. That year, 1949, coincided with the rise of the Chinese communists, who regarded Norbu as a prime target.

Chinese soldiers invaded eastern Tibet, where Kumbum was, and turned the province into what Dalai Lama biographer Pico Iyer called "the largest gulag in the world". As Iyer reported, soldiers loyal to the Communist dictator, Mao Zedong, imprisoned one in 10 Tibetans and caused the deaths of one in five - more than one million people - through starvation, torture and execution.

The Chinese authorities placed Norbu under house arrest and demanded that he travel to the capital Lhasa to denounce the Dalai Lama and kill him if he refused to step down. In return, the Communist government said it would make Norbu a governor general.

Norbu pretended to co-operate and arrived in Lhasa a few days before his brother's enthronement.

As the Dalai Lama wrote decades later: "As soon as I set eyes on him, I knew that he had suffered greatly. He was in a terrible state, extremely tense and anxious." He listened in shock as Norbu related the Chinese demands. Norbu then urged his brother to seek foreign support for Tibet and to fight back with military force. Although the Buddha forbids killing, Norbu said that violence would be justified under the circumstances. He renounced his monastic vows and declared his intent to go abroad as an emissary for their besieged country.

Norbu escaped on horseback through the Himalayas in 1950 and eventually joined a CIA project to train Tibetan Khampa tribesmen as guerrillas. The operation was unsuccessful.

In 1957, President Eisenhower granted Norbu political asylum. Three years later, he married the sister of a high lama and lived for a brief time in Seattle before accepting a job as curator of Tibetan artefacts at the Museum of Natural History in New York.

He became a US citizen during this period.Norbu returned to Tibet only once, in 1980, at the invitation of the Chinese government.

He found the Chinese presence stifling and said he regretted the visit. "Tibet doesn't exist," he told an interviewer later. In addition to his brother, son Jigme and wife, Kunyang Norbu, Norbu is survived by his sons, Lhundrup and Kunga; a sister, Jetsun Pema; brothers Gyalo Thondup and Ngari Rinpoche; and three grandchildren.